Officials with the FDA have granted breakthrough therapy designation to eltrombopag (Promacta, Novartis) for first-line use, in combination with standard immunosuppressive therapy, in patients with severe aplastic anemia (SAA), the company announced in a press release.

Promacta has already been approved as second-line therapy in the refractory setting in SAA, as well as for the treatment of adults and children with chronic immune thrombocytopenia (ITP) who are refractory to other treatments. It is marketed as Revolade in countries outside of the United States.

According to research conducted by Heart, Lung and Blood Institute of the National Institutes of Health, data demonstrated that 52% of patients with treatment-naïve SAA achieved complete response at 6 months when treated with eltrombopag at the initiation of and concurrently with standard immunosuppressive treatment, with an overall response rate of 85%.

Up to one-third of patients do not respond to current therapies for SAA or relapse, causing symptoms that can be debilitating to return, according to Novartis.

“Promacta is a promising medicine that, if approved for first-line use in severe aplastic anemia, may redefine the standard of care for patients with this rate and serious bone marrow condition,” Samit Hirawat, MD, Head, Novartis Oncology Global Drug Development, said in the press release.

SAA is a rare blood disorder in which a patient’s bone marrow fails to produce enough red blood cells, white blood cells, and platelets. Symptoms and complications such as fatigue, trouble breathing, recurring infections, and abnormal bruising or bleeding can occur.